PHOENIX -- The D-backs have played 161 games over the past six months, but whether they get to play a seventh month could hinge on what happens in Game No. 162 on Sunday.

Arizona is in this position after it was stunned by the Padres, 5-0, on Saturday night at Chase Field.

If the D-backs win their regular-season finale on Sunday, they would need some help but still have a decent chance to make the postseason as an NL Wild Card team. If they lose on Sunday, one more win by the Mets either on Sunday against the Brewers or in Monday's doubleheader against the Braves would eliminate the D-backs.

The D-backs seemingly were headed toward a postseason spot a week ago but have dropped five of their past six games. They went from controlling their own path to needing help just to get in.

"We've got to get it to turn," D-backs manager Torey Lovullo said. "We got one chance tomorrow, and we got to go out there and find a way to make that worm turn."

It's a quick turnaround for the D-backs, who have to find a way to put what can be described only as a stunning loss behind them.

The Padres, having already clinched the top NL Wild Card spot, sat half their regular players and called up Randy Vásquez to start the game. That seemed like an ideal situation for the D-backs, except Vásquez was dominant for six innings while allowing just one hit and one walk.

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The D-backs lead all of baseball in runs scored this year. With so much on the line, Lovullo felt like his hitters may have been pressing at the plate.

"My message would be, if I were speaking to the players right now, is just go out there, control the zone, control the at-bat by controlling the zone, don't try and do too much," Lovullo said. "Don't try to be the hero.

“We are a damn good offensive team, and I know their pitcher had it going on today, but I felt like we were trying to roll it up all into a ball and make it happen right now."

Eduardo Rodriguez matched Vásquez before Lovullo gave him a quick hook with two outs in the fifth inning.

The move was reminiscent of the aggressive way Lovullo managed his pitching staff last year during the run to the World Series. He felt like he had good matchups with the bullpen Saturday.

All worked according to plan until the ninth. Justin Martinez retired all four batters he faced, but Lovullo replaced him with one out in the ninth to go to A.J. Puk.

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The left-hander had been a dominant force since coming over at the Trade Deadline. In 29 games for Arizona, Puk had thrown 27 innings and allowed just one run and 12 hits.

So when the left-handed-hitting David Peralta managed to bloop a single to center field to greet Puk, it seemed unusual. But what came next was stunning, as Kyle Higashioka followed with a homer to give San Diego a 2-0 lead.

"Last night, I didn't get a hit off him, but I thought I saw the ball pretty decent," Higashioka said. "So I was just looking for something down the middle. The slider kind of popped on him. Luckily, I recognized it early."

Rookie Brandon Lockridge followed with another homer, the first of his career. After Lovullo brought in Scott McGough, the righty allowed a two-run homer. Suddenly, the Padres were up 5-0.

"They both hit sliders there," Puk said. "Just one of those things. They put some good swings on the ball. They're good hitters, and it wasn't my day today."

Which leaves the D-backs with one game left and everything on the line.